黄土丘陵区不同林龄刺槐养分利用特征和林分质量研究  

Nutrient utilization characteristics and stand quality of Robinia pseudoacacia at different stand ages in the loess hilly region of northwestern China

作　　者：芦东旭 耿雪琪 崔子怡 王诗语 王丽娜[3] 于永强 唐亚坤[3] Lu Dongxu;Geng Xueqi;Cui Ziyi;Wang Shiyu;Wang Lina;Yu Yongqiang;Tang Yakun(Research Center of Soil and Water Conservation and Ecological Environment,Chinese Academy of Sciences and Ministry of Education,Yangling 712100,Shaanxi,China;University of Chinese Academy of Sciences,Beijing 100049,China;Northwest Agricultural and Forestry University,Yangling 712100,Shaanxi,China)

机构地区：[1]中国科学院教育部水土保持与生态环境研究中心,陕西杨凌712100 [2]中国科学院大学,北京100049 [3]西北农林科技大学,陕西杨凌712100

出　　处：《北京林业大学学报》2023年第12期90-99,共10页Journal of Beijing Forestry University

基　　金：国家自然科学基金项目(41977425);西北农林科技大学“大学生创新创业训练计划”项目(S202210712334、X202210712555)。

摘　　要：【目的】刺槐因其固氮能力强、生长速度快和耐贫瘠等特点,被引入黄土高原进行水土保持和生态修复。研究黄土丘陵区不同林龄刺槐人工林的养分利用特征和林分质量,以期为该地区人工林的林分质量评价与合理经营提供理论依据。【方法】调查了黄土丘陵区纸坊沟流域13、25、33和43年林龄刺槐人工林的林分结构及林下植被多样性,测定了刺槐叶、枝、根和土壤的碳(C)、氮(N)、磷(P)含量,并计算了刺槐叶片的养分利用效率和再吸收效率及各器官N、P的化学计量内稳性,用于分析各林龄刺槐人工林的林分质量指数。【结果】(1)叶片和土壤的N、P含量随林龄的增加显著升高(P<0.05),4个林龄刺槐叶片的N∶P均大于20。叶片的N、P利用效率随林龄的增加显著降低,N、P再吸收效率随林龄的增加显著升高(P<0.05),且叶片P的养分利用效率和再吸收效率均高于N。(2)刺槐各器官的N、P和N∶P的内稳性及林下植被多样性指数在林龄25年时均达到最大。(3)25年林龄刺槐人工林的林分质量指数显著高于其他林龄(P<0.05)。【结论】不同林龄刺槐的生长主要受P的限制,刺槐通过调整养分利用特征改变了各器官N、P含量及其内稳性。25年林龄刺槐各器官较高的N、P和N∶P的内稳性以及林下植被多样性,导致了该林龄最高的林分质量指数。[Objective]Robinia pseudoacacia has been introduced to the Loess Plateau for soil and water conservation and ecological restoration because of its strong nitrogen fixation ability,fast growth speed and barren resistance.This study focused on the nutrient utilization characteristics and stand quality of R.pseudoacacia plantation at different ages in the loess hilly region,to provide theoretical basis for the evaluation and rational management of this plantation.[Method]The stand structure and diversity of understory vegetation were investigated for R.pseudoacacia in 13,25,33 and 43-years plantations in Zhifanggou Watershed of northwestern China.The contents of C,N and P in leaves,branches,roots of R.pseudoacacia and soil were determined.In addition,the leaf nutrient use and resorption efficiency of R.pseudoacacia and the stoichiometric internal stability of N and P in leaves,branches,and roots were calculated,to evaluate the stand quality index of R.pseudoacacia plantation at different stand ages.[Result](1)The N and P of content of R.pseudoacacia leaves and soil were significantly increased with increased stand age(P<0.05),and the leaves N∶P were higher than 20 among all stand ages.The leaf nutrient use efficiency of N and P was significantly decreased;however,the leaf nutrient resorption efficiency of N and P significantly were significantly increased with increased stand age(P<0.05).The leaf nutrient use and resorption efficiency of P were higher than those of N.(2)Both the internal stability of N,P elements and N∶P in different organs of R.pseudoacacia and the diversity index of understory vegetation reached the maximum value at 25-years plantations;(3)The stand quality index of 25-year-old R.pseudoacacia plantation was significantly higher than other stand ages(P<0.05).[Conclusion]The growth of R.pseudoacacia is mainly limited by P content,R.pseudoacacia changes N,P content and internal stability of various organs by adjusting nutrient utilization characteristics.Both the maximum N,P and N∶P internal st

关 键 词：刺槐 林龄 生态化学计量学 内稳性 养分利用特征 林分质量指数 

分 类 号：S792.26[农业科学—林木遗传育种]